1. Field of the Invention
The invention relates to the art of casting concrete products, and more particularly, relates to method and apparatus for producing a concrete panel having a fractured rib finish.
2. Description of the Prior Art
Machine extruded, precast structural concrete panels may be provided with a variety of architectural surface finishes. One popular architectural surface finish for precast panels is the ribbed top finish which may be produced automatically during casting, for example as disclosed in our co-pending application Ser. No. 722,586. A variation of the fractured rib finish is the hammered rib finish which is produced by manually hammering and chiseling the ribs to break away portions of the ribs and expose the underlying aggregate material. This procedure provides an aesthetically pleasing architectural finish comprising alternate strips of a relatively smooth surface and a relatively rough exposed aggregate surface. The manual hammering procedure is extremely tedious and substantially increases the installation cost of the panels. Furthermore, since the hammering procedure is usually carried out after the panels have been installed at the job site, the total time required for completion of construction is also increased.